The development, success, and widespread use of cephalosporin antibiotics in recent years have led to the emergence of a number of resistant organisms. The challenge of the resistance offers opportunities for drug design in this area as well as creates the need for new .beta.-lactam antibiotics.
Antibacterial compounds containing a cephem moiety which have a vinyl substituent or a mono-substituted vinyl group at the 3-position have been found to have broad spectrum antibacterial activity and to be orally active. Examples can be found in U.S. Pat. No. 4,409,214.
An object of the present invention is to prepare a cephem moiety having a 3-olefinic group to which is directly attached an unsubstituted or substituted heterocyclic ring to obtain superior broad spectrum antibacterials which can be administered parenterally and orally.